Revert "fix typos"

This reverts commit 32902dc029157e4ee2a5d24466f10ae9f31849e5.
Revert "Change of basic data structure in master, remove of database. fix bugs due to passing reference of list as parameters to functions. Tested until step of mapping."

This reverts commit 39de7506d58c3f2e8eba1a219035a36f3fb0f4c4.

Conflicts:

	wukong/master/wkpf/mapper.py